We have all been on the roads with tractor-trailers, semi trucks, big rigs, and 18-wheelers. Even though they are fewer in numbers than standard passenger vehicles, truck accidents cause more damages and serious injuries. Therefore it is good to know the primary causes of semi-truck accidents.
Negligence by Drivers and Trucking Companies
A major cause of semi-truck accidents in California stems from negligence by both truck drivers and their employers. This negligence can take many forms, each significantly increasing the risk of a catastrophic crash.
One of the most common issues is inadequate training. Commercial drivers must undergo specialized instruction to operate large trucks safely, but some trucking companies fail to ensure drivers meet these standards. Without proper training, drivers may lack the skills to handle emergency maneuvers, adverse weather, or steep California highways.
Additionally, negligent hiring practices are a persistent problem. Some companies hire drivers with a history of traffic violations or substance abuse, placing profit ahead of public safety. The failure to conduct thorough background checks or review driving records can have deadly consequences.
Violating Hours of Service (HOS) regulations—designed to prevent driver fatigue—is another frequent form of negligence. Companies that pressure drivers to exceed legal driving limits or skip required breaks contribute directly to drowsy driving, which is a leading factor in truck crashes.
Top 9 Common Causes of Semi-Truck Accidents
1. Speeding
As usual, speeding is one of the biggest causes of truck accidents. A truck driver may be more prone to speeding than an average passenger driver. A truck driver makes a living by getting to his destinations on time. The more cargo the driver transports, the more money he makes. The opposite is also true. If the vehicle is late, there are penalties, which in many cases involve money. Truck drivers may have a tendency to press the gas pedal a little more, which can lead to severe consequences to other drivers.
2. Reckless or Aggressive Driving
As with speeding, a truck driver may be more subject to drive aggressively to make deliveries on time. Drivers need to remember large trucks can be 80 feet long carrying close to 40 tons of cargo. This means stopping distances and turning radiuses are much different in a big rig compare to a standard car. Being aggressive behind the wheel of an 18-wheeler may lead to serious injuries.
3. Impairment
Truck drivers are subject to aggressive screening. Still, impaired driving happens. The law in California states it is illegal to operate a vehicle requiring a commercial driver’s license (CDL) with a blood alcohol level of 0.04 percent or above, which is half the standard for a passenger driver. However, any traces of blood alcohol level in a commercial driver’s system may impair his judgment on the roadways.
4. Driver Fatigue
Over 4,000 people die each year from truck accidents due to driver fatigue. Driver fatigue is a factor in 13% of large truck crashes. Fatigue can be due to all sort of physical and mental reasons. Lack of adequate sleep, long work hours, tough work conditions, and non-driving activities are some of the reasons that cause fatigue. California has new rules in place to help drivers get the rest they need. One rule makes drivers take a 30-minute break every 8 hours and another rule reduces the maximum number of driving hours per week from 82 to 70.
5. Defective or Damaged Equipment
There are many moving parts on 18-wheelers, which leaves more to break. Two equipment failures that cause crashes are brake issues and tire problems. Based on government data, equipment failure is responsible for 35% of large truck crashes.
6. Overloaded Cargo
Braking and maneuvering become more difficult when a truck’s load is too heavy. An overloaded truck contributes wear and tear on its equipment bring the brakes and tires to failure quicker than a properly loaded truck. Even distribution of cargo loads is essential for balance. Overloading one side of a truck may cause it overturn and rollover.
7. Driver Inexperience
In California, large truck drivers need to complete a physician’s medical exam, pass a written exam and a road skills test to receive a commercial drivers license. Even with a proper license, a driver may not have enough experience and confidence to be driving a large truck.
8. Unfamiliar with Area
The Federal Motor Carrier Safety Administration identified drivers’ unfamiliar with area as a factor in over 3 percent in large truck collisions. When a driver is unfamiliar with an area, the driver’s attention may be diverted from the vehicles on the road to street signs.
9. Weather and Road Conditions
Road conditions play a big role in the handling and performance of a vehicle. Snowy, icy, or even wet roads may make it tough to drive, especially braking and turning. In addition, weather may limit a driver’s visibility making it important to drive cautiously.
For what it’s worth, many of the same things that cause car accidents cause truck accidents. It is the results that may be dramatically different.
Role of Passenger Vehicles in Truck Accidents
While much attention is rightfully placed on truck driver behavior, the actions of passenger vehicle drivers also contribute significantly to semi-truck accidents in California.
Smaller vehicles often make unsafe maneuvers around trucks due to underestimating their size and limitations. For instance, cutting off a truck too closely can prevent the truck driver from stopping in time, especially on high-speed California freeways.
Another risky behavior is following too closely (tailgating). Semi-trucks have large blind spots, and passenger cars driving too closely behind or beside a truck risk being completely invisible to the driver.
Sudden lane changes, especially without signaling, are also dangerous. Trucks require much longer distances to slow down or swerve safely, making abrupt moves by passenger cars a serious hazard. Educating all drivers on how to share the road with large trucks is essential for reducing accidents.
Liability in California Semi-Truck Accidents
Determining who is liable in a California truck accident can be more complex than a typical car crash. Liability often extends beyond just the driver.
Trucking companies can be held responsible for the actions of their drivers, particularly if they failed to ensure proper training, vehicle maintenance, or compliance with federal safety laws. In some cases, companies may have directly encouraged unsafe driving practices through unrealistic delivery schedules.
Vehicle manufacturers or maintenance contractors may also share liability if a mechanical failure—such as brake failure or tire blowout—caused the accident. Likewise, cargo loaders can be at fault if improperly secured freight shifted during transit and caused the truck to lose control.
In rare instances, government entities could be liable if poor road conditions, lack of signage, or defective highway design contributed to the accident.
Understanding liability is critical for victims pursuing compensation, and working with an experienced truck accident attorney can help uncover every party that may be legally responsible.
Data Collection and Analysis in Truck Accident Cases
Effective truck accident investigations in California rely on detailed data collection and crash analysis to determine the true causes of the incident.
Police reports and witness statements are just the beginning. Today’s investigations often involve electronic data recorders (EDRs) or “black boxes” that capture speed, braking patterns, and other driver inputs moments before a crash.
Scene reconstruction experts may use skid marks, vehicle positions, and environmental factors to recreate the event and identify key contributing factors.
Another powerful tool is relative risk analysis, which assesses how various factors—like speeding, fatigue, or weather—statistically increase the likelihood of a crash. This data-driven approach helps attorneys and investigators determine fault and build a solid case for liability.
Collecting and preserving evidence quickly is vital, as trucking companies may move fast to repair vehicles or limit access to internal records. For accident victims, timely legal intervention ensures critical evidence is not lost.
Critical Events That Commonly Lead to Truck Accidents
Research from the Federal Motor Carrier Safety Administration (FMCSA) identifies several “critical events” that most frequently lead to semi-truck accidents, many of which are particularly relevant to California’s roadways.
- Running Out of the Travel Lane: This includes trucks drifting into adjacent lanes or onto the shoulder, often due to driver inattention, fatigue, or overcorrection. With California’s busy highways, these maneuvers can result in severe multi-vehicle collisions.
- Vehicle Loss of Control: Causes may include poor road conditions, equipment failure, speeding, or cargo shifts. When a truck loses control, the results can be devastating, especially on mountainous roads like those found in Northern and Central California.
- Rear-End Collisions: These often occur when a truck cannot stop in time due to its size and weight. In California’s stop-and-go traffic, especially in urban areas like Los Angeles or San Francisco, rear-end crashes involving trucks are a major concern.
Understanding these critical events helps target prevention efforts—whether through better training, stricter enforcement, or improved vehicle technologies.